I often switch on my Geyser and forget to switch it off. Result - waste of power, money etc.
Typically, we switch on the geyscer for a particular duration - say 15 mins, 20 mins etc. Now, why not have the Geyser switch itself designed like a rotary knob with minute marking (may be upto 60 mins), so that we can just toggle to the amount of time we want the geyser to be ON and then, it will turn off automatically after that. The knob could just have a coil spring like the analog stop watches - It will manually turn back from the preset time and stop when it reaches zero!